The present invention is directed to a robotic process for properly aligning a vehicle panel during a vehicle assembly process. More particularly, the present invention is directed to a robotic process whereby a vehicle panel can be removed from a temporary storage position, such as from a delivery cart, and properly oriented/positioned for robotic pickup and transfer to a vehicle.
Vehicle panels, such as hood skins, are typically delivered to an assembly line via some delivery system. Commonly such panels are delivered on carts that are designed to receive the panels in a delivery and unload section of the assembly plant, and to securely transport the panels to an assembly line where they will be used or installed to a vehicle. These carts may be automated or they may be transported to the desired location by workers using tow motors, tuggers, or various other driven vehicles.
The aforementioned carts are typically designed to ensure that a given panel, or plurality of panels, can be securely transported to a desired location without damage and without the risk of a panel falling from the cart. However, it is difficult to produce such a cart that can repeatedly guarantee the exact position of the panels upon arrival. Additionally, panels may be unloaded from these carts to a temporary storage position prior to use. Consequently, panels may await pickup in somewhat different positions and/or orientations.
Generally, then, it is necessary to reorient/reposition such panels prior to their installation to a vehicle. In other words, it is generally necessary to remove such a panel from a delivery cart or other temporary storage position and to place the panel in a particular orientation/position so that it can be properly transferred to a vehicle by a robot.
Reorientation may occur in a number of ways. For example, a worker may manually remove each panel from its initial temporary storage position and subsequently orient/position it for proper installation to a vehicle. This may be done with the aid of some sort of alignment jig or fixture that allows the worker to gauge the orientation of the panel. Alternatively, a panel may be manually or robotically removed from its initial temporary storage position and placed in an automated alignment fixture that functions to properly orient the panel.
One known version of a related automated fixture uses multiple actuators to properly position a component. More specifically, the fixture is provided with multiple actuators that are located to be located outward of the periphery of the component once it has been set into the fixture. Subsequent extension of the actuators thereafter results in contact with various sides of the component, eventually forcing it into the desired orientation and position. One or more hard stops or other contactors may be employed in certain embodiments of such fixtures to help guarantee position. Once properly positioned, the actuators may be retracted and the component can be picked up by a part installer and installed to the vehicle.
More simplistic embodiments of a part positioning fixture have attempted to use gravity as the driving force for properly orienting a panel. Such a fixture is usually designed with at least one angle, and may possess a compound angle that is provided to produce movement of the panel into proper position once it has been deposited to the fixture. Such a fixture also commonly includes one or more hard stops against which the panel can slide once deposited thereto.
Each of these known part orienting fixtures/systems suffers from various drawbacks, however. For example, the former actuator-employing fixture cannot generally accommodate panels of more than one size and or shape because supports designed for one panel may not correspond to the size and/or shape of a dissimilar panel. Further, the actuators are normally designed to contact corresponding portions of the panels only through a specific and predetermined distance. Thus, in certain circumstances, a panel of dissimilar size and/or shape may simply be too large to fit on the fixture. In other circumstances, it is possible that the movement of the actuators may be insufficient to fully move the panel into position. Even in the event that the actuator movement is adjustable, it is at least required to adjust the stop points thereof each time a new panel is loaded onto the fixture. Additionally, on embodiments employing hard stops, it may not be possible to locate Hard stops to accommodate more than one panel. As a result of these difficulties, it is typically necessary that a separate actuator-type fixture be designed for each panel of interest. Obviously, this is both space consuming and expensive—particularly when dealing with large panels.
The latter-mentioned and known gravity-based fixture/system has also proven to be unacceptable. First, it has been found that gravity alone is often sufficient to cause proper displacement of the component. More specifically, it has been observed that high frictional forces often exist between contacting portions of the panel and the fixture—particularly when the panel is of significant weight. The result of this problem is that the panel commonly fails to slide fully into the proper position. Further, such fixtures typically rely on momentum to assist with sliding of the panel. That is, the panel is often dropped on the fixture from some slight distance, thereby facilitating its movement. This has also proven to be problematic, as dropping of the panel often results in damage thereto (particularly if the panel is of significant weight).
Hence, what is desired is a system and process by which a panel can be removed from a delivery cart or other temporary storage position and quickly, easily and repeatably oriented/positioned for subsequent pickup and transfer by a robotic part installer. The system and process of the present invention satisfies this need. A system and process of the present invention can be used to properly orient/position a variety of different types of components, but is especially well suited for use with vehicle panels. The same system/process of the present invention may also be capable of use with various sized and shaped panels of a particular type (e.g., hood skins).